Se for JBOSS vc deve consigurar um datasource, por exemplo, um postgre-ds.xml que fica no diretório onde fica o ear (normalmente /default/)
<datasources>
<local-tx-datasource>
<jndi-name>PostgresTesteDS</jndi-name>
<connection-url>jdbc:postgresql://localhost/teste</connection-url>
<driver-class>org.postgresql.Driver</driver-class>
<user-name>FBI_intend_dbrest</user-name>
<password>ueps_cia</password>
<min-pool-size>80</min-pool-size>
<!-- The maximum connections in a pool/sub-pool -->
<max-pool-size>90</max-pool-size>
<!-- sql to call when connection is created
<new-connection-sql>some arbitrary sql</new-connection-sql>
-->
<!-- sql to call on an existing pooled connection when it is obtained from pool
<check-valid-connection-sql>some arbitrary sql</check-valid-connection-sql>
-->
</local-tx-datasource>
</datasources>